A novel method to standardise serum IgA measurements shows an increased prevalence of IgA deficiency in young children with recurrent respiratory tract infections

• Published in: Clinical & translational immunology 2021, Vol.10 (11), p.e1344-n/a
• Main Authors: Koenen, Mischa H, Bosma, Madeleen, Roorda, Udo A, Wopereis, Fabiënne MY, Roos, Anja, der Vries, Erhard, Bogaert, Debby, Sanders, Elisabeth AM, Boes, Marianne, Heidema, Jojanneke, Montfrans, Joris M, Balemans, Walter AF, Holten, Thijs C, Verhagen, Lilly M
• Format: Article
• Language: English
• Subjects: Age; Asymptomatic; case–control study; Celiac disease; Children; IgA deficiency; Immunoglobulin A; Immunoglobulins; Infections; Laboratories; Original; reference values; Respiratory tract diseases; Respiratory tract infection; respiratory tract infections
• ISSN: 2050-0068; 2050-0068
• DOI: 10.1002/cti2.1344

Objectives While physicians are often confronted with immunoglobulin A (IgA) deficiency in children with recurrent infections, the clinical relevance of this finding is unclear. Large‐scale studies examining the significance of IgA deficiency in children are hampered by differences in techniques for measuring IgA and the physiological increase of IgA with age. Both result in a variety of reference values used for diagnosing IgA deficiency. We propose a new laboratory‐independent method to accurately compare IgA measurements in children of varying ages. Methods We present a method to standardise IgA values for age and laboratory differences. We applied this method to a multicentre case–control study of children under the age of seven suffering from recurrent respiratory tract infections (rRTI, cases) and children who had IgA measured as part of coeliac disease screening (controls). We defined IgA deficiency as serum IgA measurements